scholarly journals Effects of Diisocyanate Structure and Disulfide Chain Extender on Hard Segmental Packing and Self-Healing Property of Polyurea Elastomers

Polymers ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 838 ◽  
Author(s):  
Ting Li ◽  
Tianze Zheng ◽  
Jiarui Han ◽  
Zhanli Liu ◽  
Zhao-Xia Guo ◽  
...  
Keyword(s):  
Disulfide Bonds ◽  
Aliphatic Amine ◽  
Chain Extender ◽  
Hexamethylene Diisocyanate ◽  
Self Healing ◽  
Segmental Dynamics ◽  
Chain Mobility ◽  
Healing Property ◽  
Chain Extenders ◽  
Hard Segments

Four linear polyurea elastomers synthesized from two different diisocyanates, two different chain extenders and a common aliphatic amine-terminated polyether were used as models to investigate the effects of both diisocyanate structure and aromatic disulfide chain extender on hard segmental packing and self-healing ability. Both direct investigation on hard segments and indirect investigation on chain mobility and soft segmental dynamics were carried out to compare the levels of hard segmental packing, leading to agreed conclusions that correlated well with the self-healing abilities of the polyureas. Both diisocyanate structure and disulfide bonds had significant effects on hard segmental packing and self-healing property. Diisocyanate structure had more pronounced effect than disulfide bonds. Bulky alicyclic isophorone diisocyanate (IPDI) resulted in looser hard segmental packing than linear aliphatic hexamethylene diisocyanate (HDI), whereas a disulfide chain extender also promoted self-healing ability through loosening of hard segmental packing compared to its C-C counterpart. The polyurea synthesized from IPDI and the disulfide chain extender exhibited the best self-healing ability among the four polyureas because it had the highest chain mobility ascribed to the loosest hard segmental packing. Therefore, a combination of bulky alicyclic diisocyanate and disulfide chain extender is recommended for the design of self-healing polyurea elastomers.

Synthesis and properties of responsive self-healing polyurethane containing dynamic disulfide bonds

2021 ◽  
pp. 095400832110228
Author(s):  
Qiqi Qu ◽  
Hua Wang ◽  
Jing He ◽  
Yunsheng Da ◽  
Menghan Zhu ◽  
...  
Keyword(s):  
Disulfide Bonds ◽  
Meaningful Work ◽  
Hexamethylene Diisocyanate ◽  
Self Healing ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Characterization Methods ◽  
Raman Scattering Spectroscopy ◽  
Ph Response ◽  
Healing Efficiency

The polymers with pH responsiveness and temperature sensitivity exhibit important applications in many fields. To endow the responsive polymers with self-healing is meaningful work, which contributes to increase their service life and reduce waste of resources significantly. In this research, a series of pH-responsive polyurethanes containing dynamic disulfide bonds and carboxylic acid functional groups were prepared by mixing polycaprolactone diol (PCL), hexamethylene diisocyanate (HDI), 2,2-dimethylolbutyric acid, and bis(2-hydroxyethyl) disulfide. The structure of the polymer was confirmed by some characterization methods such as infrared absorption spectroscopy, Raman scattering spectroscopy, X-ray diffraction, and differential scanning calorimetry. Many performances of the polymer such as the contact angle, thermal stability, mechanics, and self-healing properties can be adjusted by changing the functional units of polyurethanes. The dynamic disulfide bonds in the main chain were observed no harm to the pH response performance, instead which were beneficial to the promotion of heat resistance, tensile properties, and self-healing performance of polyurethane. The elongation at break and the tensile strength are increased by 85.3% and 54.9%, respectively. All the polyurethane exhibited considerable self-healing effects at 110°C, with the highest healing efficiency reaching 93.7%, as a result of the dissociation of hydrogen bonds and the exchange reaction of disulfide bonds.

Thermal, mechanical and wettability properties of some branched polyetherurethane elastomers

e-Polymers ◽  
2009 ◽  
Vol 9 (1) ◽  
Author(s):  
Stelian Vlad ◽  
Iuliana Spiridon ◽  
Cristian Vasile Grigoras ◽  
Mioara Drobota ◽  
Alexandra Nistor
Keyword(s):  
Dynamic Contact Angle ◽  
Dynamic Contact ◽  
Chain Extender ◽  
Hexamethylene Diisocyanate ◽  
Isophorone Diisocyanate ◽  
Characterization Methods ◽  
H Nmr ◽  
Chain Extenders ◽  
Tga And Dsc

AbstractIn this study three series of polyetherurethanes (PEU) based on Terathane ® (polytetramethyleneetherglycol - PTMEG, Mn 1400) as polyol; isophorone diisocyanate (IPDI), 4,4’-methylene-bis-(cyclohexyl-isocyanate) (HMDI) and hexamethylene diisocyanate (HDI) as aliphatic diisocyanate components; 1,4- butanediol (BD) and glycerin (Gly) as chain extenders were synthesized. The glycerin as triol is responsible for the crosslinking structures. All polyether urethanes were synthesized by prepolymer method. The PTMEG was reacted with diisocyanate to realize a diisocyanate-terminated prepolymer, which in next step was extended with blend of the 1,4-butanediol (BD) and glycerin (Gly) in different proportion. The influence of the diisocyanate structure and chain extender functionality on the thermal, mechanical and wettability properties were the aim of this study. The physical, mechanical and wettability properties of these polymers were measured according to standard methods. All polymers were characterized by conventional characterization methods. Different methods of thermal analysis (TGA and DSC) were used for characterization. Wettability was estimated by determination of the dynamic contact angle. The structures were confirmed by FTIR and H-NMR analysis. The results show that the thermal stability, mechanical and wettability properties of the final products are influenced by the diisocyanate and chain extenders nature.

scholarly journals Preparation and Characterization of Isosorbide-Based Self-Healable Polyurethane Elastomers with Thermally Reversible Bonds

Molecules ◽  
2019 ◽  
Vol 24 (6) ◽  
pp. 1061 ◽  
Author(s):  
Han-Na Kim ◽  
Dae-Woo Lee ◽  
Hoon Ryu ◽  
Gwang-Seok Song ◽  
Dai-Soo Lee
Keyword(s):  
Elevated Temperatures ◽  
Phenyl Isocyanate ◽  
Chain Extender ◽  
The Self ◽  
Self Healing ◽  
Polyurethane Elastomers ◽  
Wide Range ◽  
Chain Extenders ◽  
Product Durability

Polyurethane (PU) is a versatile polymer used in a wide range of applications. Recently, imparting PU with self-healing properties has attracted much interest to improve the product durability. The self-healing mechanism conceivably occurs through the existence of dynamic reversible bonds over a specific temperature range. The present study investigates the self-healing properties of 1,4:3,6-dianhydrohexitol-based PUs prepared from a prepolymer of poly(tetra-methylene ether glycol) and 4,4′-methylenebis(phenyl isocyanate) with different chain extenders (isosorbide or isomannide). PU with the conventional chain extender 1,4-butanediol was prepared for comparison. The urethane bonds in 1,4:3,6-dianhydrohexitol-based PUs were thermally reversible (as confirmed by the generation of isocyanate peaks observed by Fourier transform infrared spectroscopy) at mildly elevated temperatures and the PUs showed good mechanical properties. Especially the isosorbide-based polyurethane showed potential self-healing ability under mild heat treatment, as observed in reprocessing tests. It is inferred that isosorbide, bio-based bicyclic diol, can be employed as an efficient chain extender of polyurethane prepolymers to improve self-healing properties of polyurethane elastomers via reversible features of the urethane bonds.

scholarly journals Synthesis and Characterization of Healable Waterborne Polyurethanes with Cystamine Chain Extenders

Molecules ◽  
2019 ◽  
Vol 24 (8) ◽  
pp. 1492 ◽  
Author(s):  
Dae-Il Lee ◽  
Seung-Hyun Kim ◽  
Dai-Soo Lee
Keyword(s):  
Scratch Test ◽  
Chain Extender ◽  
Self Healing ◽  
Hot Press ◽  
High Mechanical Strength ◽  
Waterborne Polyurethanes ◽  
Before And After ◽  
Chain Extenders ◽  
A Chain

In this study, environmentally friendly, self-healing waterborne polyurethanes (WPUs) were prepared based on the disulfide metathesis reaction in cystamine. The cystamine acted as a chain extender in the WPU film, which showed a high mechanical strength of 19.1 MPa. The possibility of self-healing reaction was simultaneously modeled via liquid chromatography–mass spectrometry (LC-MS). WPU was confirmed to self-heal a surface crack thermally after a scratch test, and the efficiency was measured by comparing the mechanical properties before and after a cut-and-healing test. In addition, the disulfide-thiol exchange reaction was confirmed to occur in WPU with cystamine as a chain extender and 2-mercaptoethanol. Hot press tests confirmed the possibility of reprocessing the WPU. The WPU incorporating disulfide groups showed great potential as a smart self-healing material.

Effect of chain extender on microphase structure and performance of self‐healing polyurethane and poly(urethane‐urea)

2021 ◽  
pp. 51371
Author(s):  
Yulong Wang ◽  
Yaqiong Li ◽  
Maoyong He ◽  
Jingjing Bai ◽  
Bingxiao Liu ◽  
...  
Keyword(s):  
Chain Extender ◽  
Self Healing ◽  
And Performance

scholarly journals Characterization of Steel Slag Filler and Its Effect on Aging Resistance of Asphalt Mastic with Various Aging Methods

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 869
Author(s):  
Minghua Wei ◽  
Shaopeng Wu ◽  
Haiqin Xu ◽  
Hechuan Li ◽  
Chao Yang
Keyword(s):  
Particle Size ◽  
Surface Characterization ◽  
Steel Slag ◽  
Self Healing ◽  
Limestone Filler ◽  
Asphalt Mastic ◽  
Pore Characterization ◽  
Asphalt Mastics ◽  
Healing Property

Steel slag is the by-product of the steelmaking industry, the negative influences of which prompt more investigation into the recycling methods of steel slag. The purpose of this study is to characterize steel slag filler and study its feasibility of replacing limestone filler in asphalt concrete by evaluating the resistance of asphalt mastic under various aging methods. Firstly, steel slag filler, limestone filler, virgin asphalt, steel slag filler asphalt mastic and limestone filler asphalt mastic were prepared. Subsequently, particle size distribution, surface characterization and pore characterization of the fillers were evaluated. Finally, rheological property, self-healing property and chemical functional groups of the asphalt mastics with various aging methods were tested via dynamic shear rheometer and Fourier transform infrared spectrometer. The results show that there are similar particle size distributions, however, different surface characterization and pore characterization in the fillers. The analysis to asphalt mastics demonstrates how the addition of steel slag filler contributes to the resistance of asphalt mastic under the environment of acid and alkaline but is harmful under UV radiation especially. In addition, the pore structure in steel slag filler should be a potential explanation for the changing resistance of the asphalt mastics. In conclusion, steel slag filler is suggested to replace limestone filler under the environment of acid and alkaline, and environmental factor should be taken into consideration when steel slag filler is applied to replace natural fillers in asphalt mastic.

Iron (III) cross-linked thermoplastic nitrile butadiene elastomer with temperature-adaptable self-healing property

2021 ◽  
Vol 28 (3) ◽  
Author(s):  
Chenghao Dai ◽  
Xijuan Cao ◽  
Kai Gou ◽  
Qiyan Yin ◽  
Binjie Du ◽  
...  
Keyword(s):  
Self Healing ◽  
Healing Property

Robust Anti-Infective Multilayer Coatings with Rapid Self-Healing Property

2021 ◽  
pp. 111828
Author(s):  
Chao Zhou ◽  
Juntao Zhou ◽  
Xiaoqing Ma ◽  
Dicky Pranantyo ◽  
Jingjing Li ◽  
...  
Keyword(s):  
Multilayer Coatings ◽  
Self Healing ◽  
Healing Property
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